Script to build libpng for iOS

build-png.sh

#!/bin/sh

dobuild=1
docopy=1
doclean=1
version=1.6.9
srcdir=libpng-${version}
srcfile=${srcdir}.tar.gz
srctarball=http://sourceforge.net/projects/libpng/files/libpng16/${version}/${srcfile}/download
outdir=$(cd ../external-deps/png; pwd)
iosmin=6.0
osxmin=10.7

build() {
    sdk=$1
    arch=$2

    case $sdk in
    macosx)
        minflags="-mosx-version-min=$osxmin"
        ;;
    iphoneos)
        minflags="-mios-version-min=$iosmin"
        ;;
    iphonesimulator)
        minflags="-mios-simulator-version-min=$iosmin"
        ;;
    *)
        echo $0: Invalid sdk $sdk
        exit 10
    esac

    echo Building $sdk $arch

    cpu=$(uname -m)
    release=$(uname -r)
    host=${cpu}-apple-darwin${release}

    archout=$(pwd)/arch-${sdk}-${arch}
    rm -rf $archout
    (cd $srcdir; make distclean)
    (cd $srcdir; CPP="xcrun --sdk $sdk clang -E -arch $arch $minflags" CC="xcrun --sdk $sdk clang" CFLAGS="-arch $arch $minflags" LD="xcrun --sdk $sdk clang" LDFLAGS="-arch $arch $minflags" ./configure --host $host --prefix=$archout --disable-shared  --enable-arm-neon=off) || exit 4
    (cd $srcdir; make install) || exit 5
}

makefat() {
    inputdirs="$1"
    inputlib=$2
    outputlib=$3

    mkdir -p $(dirname $outputlib) || exit 11
    rm -f $outputlib

    lipocmd="xcrun lipo -create -output $outputlib"
    for dir in $inputdirs
    do
        infile=$dir/$inputlib
        if [ ! -f $infile ]; then
            echo $0: $infile does not exist
            exit 12
        fi
        inarch=$(xcrun lipo -info $infile | tail -1 | awk '{print $NF }')
        lipocmd="$lipocmd -arch $inarch $infile"
    done

    echo $0: Running $lipocmd
    $lipocmd || exit 14
}

if [ ! -d $outdir ]; then
    echo $0: $outdir does not exist
    exit 1
fi

if [ ! -f $srcfile ]; then
    curl $srctarball -o $srcfile || exit 1
fi

if [ ! -d $srcdir ]; then
    tar xfv $srcfile || exit 3
    if [ ! -d $srcdir ]; then
        echo $0: Failed to extract to $srcdir
        exit 4
    fi
fi

if [ $dobuild -gt 0 ]; then
    build macosx i386
    build macosx x86_64
    build iphoneos armv7
    build iphoneos armv7s
    build iphoneos arm64
    build iphonesimulator i386
fi

if [ $docopy -gt 0 ]; then
    makefat "arch-macosx-i386 arch-macosx-x86_64" lib/libpng16.a $outdir/lib/macosx/libpng.a
    makefat "arch-iphoneos-arm64 arch-iphoneos-armv7 arch-iphoneos-armv7s arch-iphonesimulator-i386" lib/libpng16.a $outdir/lib/ios/libpng.a

    for h in png.h pngconf.h pnglibconf.h
    do
        cp $srcdir/$h $outdir/include || exit 5
    done
fi

if [ $doclean -gt 0 ]; then
    rm -rf arch-* $srcdir
fi

echo $0: Done.  Please check that $outdir/lib/ios does not contain arch-specific directories